• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.860-865
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• 2012

Although biomass syngas is very low calorific gas, it is utilized by means of dual fuel combustion technology in the fields of industrial furnace and boiler as a substitute oil technology. The basic structure of duel fuel combustion burner is designed so that low caloric gas fuel is supplied around an oil burner in the middle. In the present study, three types of mixing burners were manufactured to conduct performance experiment. Low caloric gas was evenly distributed around the oil burner and the method of changing the angle of gas nozzle was applied. CO generation decreased according to the increase of the amount of air for combustion. In addition, the shapes and colors of flame changed according to the proportions of gas and oil used. Remained flame after combustion was from the lack of atomization at the exit of oil burner. Although it was difficult to maintain the optimum air ratio due to different required air ratio for oil and syngas, stable combustion was able to maintained within excess oxygen concentration of 4.7~8.2%. From this study, it was shown that the oil atomization at the exit of fuel oil nozzle was promoted by the increased rate of syngas combustion and the CO concentration in flue gas lower than only fuel oil combustion.

• New & Renewable Energy
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• v.7 no.3
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• pp.17-28
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• 2011

Biogas production and utilization are an emerging alternative energy technology. Biogas is produced from the biological breakdown of organic matter through anaerobic digestion. Biogas can be utilized for various energy sectors such as space heating, electricity generation and vehicle fuel. Especially, to be utilized as vehicle fuel, raw biogas needs to be upgraded that is mainly the removal of carbon dioxide to increase the methane content up to more than 95 ~ 97 vol% in some cases, similar to the composition of fossil-based natural gas. Usage of Biogas as a fuel of vehicles have an effect of reducing $CO_2$ emission compared to fossil fuels. Biomethane which is produced by upgrading of biogas is regarded as a good alternative energy and usage of clean energy is encouraged to deal with air pollution and waste management as well as production of clean energy. Recently, biogas projects for vehicle fuel are newly being launched and Korea government have also announced a plan for investment to develop biogas as a transport fuel. In this study, it is aimed to examine the potential feasibility of biomethane as a transport fuel. As a results, the status of biomethane, quality standard, quality characteristics, and upgrading technology of biogas were investigated to evaluate of biogas as a vehicle fuel of transportation.

• Clean Technology
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• v.21 no.4
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• pp.229-234
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• 2015

Recently, there are increasing numbers of study regarding hydrogen fuels but researches on desulfurization of diesel are rare. In this study, we performed diesel desulfurization reactor design by computation fluid dynamics simulation. By analyzing the change in flow and sulfur concentration at the outlet according to the changes in flow rate, reactor length, and reactor diameter, we have found the minimum catalyst performance for the given flow rate condition and the relation between the reactor performance and the reactor size and shape. We also studied the effects of permeability of the packed bed on the flow and sulfur concentration distribution. The present work can be utilized to design a diesel desulfurization reactor for a fuel cell used in ships. Furthermore, the present work also can be used to design low sulfur diesel supply in oil refineries and therefore contribute to the development of clean petrochemical technology.

• Clean Technology
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• v.20 no.1
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• pp.80-87
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• 2014

Numerical study was investigated to obtain the database for developing a fast pyrolysis power boiler by waste fuel. The studies with various conditions were performed using ANSYS FLUENT. Also, the fuel properties was experimentally analyzed to utilize the input parameters for numerical analysis, that were proximate and ultimate analysis, reaction kinetics included pyrolysis and combustion. The results showed that temperature, combustion and exhausted gases was changed with heating value of fuel and feeding rate. Finally, the stable operating condition by analyzing results was proposed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.739-740
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• 2007

• Journal of ILASS-Korea
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• v.20 no.2
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• pp.88-94
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• 2015

Recently, exhaust gas regulation has been gradually strengthened due to depletion of fossil fuels and environmental problem like a global warming. Due to this global problem, the demand for eco-friendly vehicle development is rapidly increasing. A clean diesel vehicle is considered as a realistic alternative. The common-rail fuel injection system, which is the key technology of the clean diesel vehicle, has adopted injection strategies such as high pressure injection, multiple injection for better atomization of the fuel. In addition, the emission regulations in the future is expected to be more stringent, which a conventional engine is difficult to deal with. One of the way for actively proceeding is the study of alternative fuels. Among them, the bio-diesel has been attracted as an alternative of diesel. So, in this study, spray characteristics of bio-diesel was analyzed in the common-rail fuel injection system with three injectors driven by different operating mechanism.

• Clean Technology
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• v.14 no.2
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• pp.144-151
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• 2008

Life cycle assessment was carried out to evaluate the environmental values of dimethylas a diesel alternative fuel with the assumption of dimethyl ether production from natural gas via synthesis gas. The whole life cycles from raw material acquisitions to the final usages of diesel and dimethyl ether were involved in the assessment. Inventory analysis showed that the most significant environmental impacts came from resource depletions and air emissions. Impact assessment revealed that dimethyl ether was environmentally better in the aspect of human health and ecosystem quality but worse in resource depletions compared with diesel fuel. Suggestions for environmental improvement of dimethyl ether as a diesel alternative fuel were prepared based on the assessment results.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.1-8
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• 2002

For gasoline engines, a three-way catalytic converter that has the maximum efficiency at stoichiometric air/fuel ratio is used to clean up the exhaust gas. So a precise air/fuel ratio control is necessary to maximize the catalytic conversion efficiency, For a transient condition, a fred-forward air/fuel ratio control method that estimates the air mass inducted into a cylinder is being used. In this study, a fuel injection map that makes an accurate air/fuel ratio control possible was constructed for the very same transient condition. For the same condition above, intake air model and fuel model were refined so that fuel injection values based on air mass through a throttle valve and intake manifold pressure are equal to the map values.

• Clean Technology
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• v.29 no.1
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• pp.53-58
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• 2023

This study shows the summary of the economic performance of excess electricity conversion to hydrogen as well as methane and returned conversion to electricity using a fuel cell. The methane production process has been examined in a previous study. Here, this study focuses on the conversion of methane to electricity. As a part of this study, capital expenditure (CAPEX) is estimated under various sized plants (0.3, 3, 9, and 30 MW). The study shows a method for economic optimization of electricity generation using a fuel cell. The CAPEX and operating expenditure (OPEX) as well as the feed cost are used to calculate the discounted cash flow. Then the levelized cost of returned electricity (LCORE) is estimated from the discounted cash flow. This study found the LCORE value was ¢10.2/kWh electricity when a 9 MW electricity generating fuel cell was used. A methane production plant size of 1,500 Nm³/hr, a methane production cost of $11.47/mcf, a storage cost of $1/mcf, and a fuel cell efficiency of 54% were used as a baseline. A sensitivity analysis was performed by varying the storage cost, fuel cell efficiency, and excess electricity cost by ±20%, and fuel cell efficiency was found as the most dominating parameter in terms of the LCORE sensitivity. Therefore, for the best cost-performance, fuel cell manufacturing and efficiency need to be carefully evaluated. This study provides a general guideline for cost performance comparison with LCORE.

• Clean Technology
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• v.15 no.1
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• pp.1-8
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• 2009

The adoption of compressed natural gas (CNG) as a vehicle fuel is a common phenomenon as it is accelerating worldwide. Increasing number of CNG driven vehicles around the world has jumped up from one million in 1996 to five million in 2006. CNG as a vehicle fuel is very popular to the end users because of its clean-burning properties and cost effective solution compared to other alternative fuels like diesel and gasoline. The use of CNG as a fuel reduces vehicular emission that is consisted of carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen ($NO_x$), carbon dioxide ($CO_2$) etc. This research highlights the characteristics of CNG vehicles, CNG arrangement in the vehicles, CNG fueling procedures and most importantly the environmental and economic factors that are highly considered as cost effective solution for the flexibility of using CNG in the automobiles.